Characterizing Clustering in Boulder Bed Channels and the Impact on Shear Stress Equations  

作　　者：Katherine Clancy Katherine Clancy(College of Natural Resources, University of Wisconsin at Stevens Point, Stevens Point, WI, USA)

机构地区：[1]College of Natural Resources, University of Wisconsin at Stevens Point, Stevens Point, WI, USA

出　　处：《Journal of Water Resource and Protection》2021年第4期283-292,共10页水资源与保护（英文）

摘　　要：Boulders and cobbles are often used in stream restoration projects to increase flow resistance and enhance channel stability and habitat diversity. Particle size metrics determined from the particle distribution are often used as a proxy for shear stress in field equations. Clustering of large particles has been thought to contribute to shear stress, but the effect of clustering is not accounted for in equations that use a representative particle size, such as the <em>D</em>₈₄. In this paper, clustering is defined using the upper tail (≥84%) in a variable called Topsum. The number of clusters, average size of clusters, and shear stress are evaluated using the proposed definition of cluster. Findings suggest that the upper tail represents the roughness height better than the commonly used proxy of <em>D</em>₈₄ for boulder bed streams (streams which have a D84 particle 0.05 - 0.15 meters).Boulders and cobbles are often used in stream restoration projects to increase flow resistance and enhance channel stability and habitat diversity. Particle size metrics determined from the particle distribution are often used as a proxy for shear stress in field equations. Clustering of large particles has been thought to contribute to shear stress, but the effect of clustering is not accounted for in equations that use a representative particle size, such as the <em>D</em>₈₄. In this paper, clustering is defined using the upper tail (≥84%) in a variable called Topsum. The number of clusters, average size of clusters, and shear stress are evaluated using the proposed definition of cluster. Findings suggest that the upper tail represents the roughness height better than the commonly used proxy of <em>D</em>₈₄ for boulder bed streams (streams which have a D84 particle 0.05 - 0.15 meters).

关 键 词：Boulder Bed Shear Stress Particle Distribution D₈₄ 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]